Revolving dredge



E. MOORE. Revolving Dredge.

No 233,365. Patented Oct. 19, I880.

Fig.1.

N-FEIERS, PHOTO-UTHOGHAFHEH, WASHINGTON D C.

UNITED STATES PATENT OFFIcE.

EDWARD MOORE, OF PORTLAND, MAINE.

REVOLVING DREDGE.

SPECIFICATION forming part of Letters Patent No. 233,365, dated October 19, 1880.

Application filed February 20, 1880.

To all whom it may concern:

Be it known that I, EDWARD MOORE, of Portland, in the county of Cumberland and State of Maine, haveinvented a new and useful Improvement in Revolving Dredges and Derricks; and I do hereby declare that the following is a full, clear, and exact description of the same.

My invention relates to dredges designed to be operated, in connection with a revolving derrick, to move masses of excavated or dredged material to a place of deposit. It is designed especially as an improvement upon the particular form of revolving and carrying derrick shown in Letters Patent granted to Moore and Wright on the 18th day of November, 1879, and numbered 221,848.

This derrick has been heretofore used in connection with an ordinary dredge and scow, the dredge being used to excavate the material and to discharge it into tubs carried upon the ends of the booms of the revolving derrick. This plan, in addition to the necessity of using other and expensive machinery besides the derrick, manifestly requires a considerable amount of additional labor besides that required for the derrick itself, and occasions some delay in discharging from the dredge-bucket into the tub of the derrick.

My object is to dispense with the additional dredging-machine and to operate the dredge directly from "the boom of the derrick itself. For this purpose I have selected the ordinary clam-shell dredge, and adapted it to operate in connection with the revolving derrick shown in Letters Patent heretofore referred to. To thus apply this form of dredge to the revolving derrick, dispensing with the tub, I connect the poles of the dredge directly to the end of the boom by means of eyebolts fixed in the boom, through the rings of which bolts the poles pass.

In the drawings accompanying this specification, Figure 1 shows a side elevation of the revolving derrick combined with the clamshell dredge. Fig. 2 shows an enlarged view of the dredge and the mode of connection with the boom of the revolving derrick.

In these figures A A represent the poles of an ordinary clam-shell dredge. They pass through the rings a a, in the boom B, the

rings being placed at a sufficient distance asunder and upon opposite sides of the boom to adapt them to the poles of the dredge, which is turned, as shown in the figures.

The chains for hoisting, as well as those for opening and closing the dredge, are carried over sheaves in the end of the boom and back to the drums or pulleys on the central platform, from which they are operated. Any number which may be desired of symmetrically-arranged and mritually-balancing booms may be used, each carrying a clam-shell dredge.

By this apparatus I am enabled to dredge mud from the bottom of rivers or other bodies of water, and to carry it, without change, from one bucket to another, from its position on one side of the derrick to the place where it is to be discharged on the other, a distance, if necessary, of two hundred and fifty feet or more, according to the length of the booms on the revolving derrick.

The derrick may be mounted upon a platform carried upon tracks on an embankment, or upon a scow or float.

It is to be understood that a suitable engine is mounted upon the revolving platform and provided with proper gearing, both for operating the dredge and for imparting rotary motion to the circular platform of the derrick, so as to move the booms which carry the dredges from one side to the other.

The platform revolves on its track with only the slight interruptions necessary to fill and empty the dredge-buckets.

Having thus described my inventiomwhat I claim as new, and desire to secure by Letters Patent, is

The combination, with a revolving derrick having symmetrically arranged booms and driving mechanism for rotating the said derrick, of the clam-shell dredges connected directly to the ends of said booms and operated by the driving mechanism, as and for the purposes set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

EDWARD MOORE.

Witnesses:

L. WARREN SEELY, FRANK MIDDLETON. 

